tests/no_syscall_test.c

   1 // SPDX-License-Identifier: MIT
   2 // SPDX-FileCopyrightText: 2024 Michael Jeanson <mjeanson@efficios.com>
   3
   4 #ifndef _GNU_SOURCE
   5 #define _GNU_SOURCE
   6 #endif
   7 #include <stdint.h>
   8
   9 #include <rseq/rseq.h>
  10
  11 #include "tap.h"
  12
  13 #define NR_TESTS 4
  14
  15 /*
  16  * Ensure the main executable has at least one TLS variable which will be
  17  * allocated before the rseq area, making sure the rseq_offset is not 0.  This
  18  * allows testing that the rseq_offset variable is properly initialized by
  19  * checking it is not 0.
  20  *
  21  * Most toolchains will add at least one main exec TLS variable but it's
  22  * currently not the case on RISC-V.
  23  */
  24 __thread int dummy_tls = -1;
  25
  26 /*
  27  * Check the state of the public symbols when the rseq syscall is unavailable.
  28  *
  29  * This test must be used with an LD_PRELOAD library to deny access to the
  30  * syscall, or on a kernel that doesn't implement the syscall.
  31  */
  32
  33 int main(void)
  34 {
  35         struct rseq_abi *rseq_abi;
  36
  37         plan_tests(NR_TESTS);
  38
  39         if (rseq_available(RSEQ_AVAILABLE_QUERY_KERNEL)) {
  40                 fail("The rseq syscall should be unavailable");
  41                 goto end;
  42         }
  43
  44         /* The rseq syscall is disabled, no registration is possible. */
  45
  46         ok(rseq_flags == 0, "rseq_flags prior to registration is 0 (%d)", rseq_flags);
  47         ok(rseq_size == 0, "rseq_size prior to registration is 0 (%d)", rseq_size);
  48         ok(rseq_offset != 0, "rseq_offset prior to registration is not 0 (%td)", rseq_offset);
  49
  50         rseq_abi = rseq_get_abi();
  51         ok((int32_t) rseq_abi->cpu_id == RSEQ_ABI_CPU_ID_UNINITIALIZED,
  52                         "rseq->cpu_id is set to RSEQ_ABI_CPU_ID_UNINITIALIZED (%d)",
  53                         (int32_t) rseq_abi->cpu_id);
  54
  55 end:
  56         exit(exit_status());
  57 }